The present invention relates to clocks, and in particular to a clock movement which is of such a reduced dimension that it can be employed in locations where a limited dimension is permitted.
A clock movement is one which is to be enclosed in a case to complete a clock, while a watch movement is one which is to be enclosed in a case to form a complete watch. As is known, clock movements are used in timepieces of large dimensions and watch movements are used in watches of comparatively smaller dimensions. Namely, an ordinary clock movement has a dimension of 56 mm.times.56 mm.times.16 mm for a rectangular one and a dimension of 50 mm.times.8 mm for a circular one. Moreover, an ordinary watch movement has a dimension of 30 mm.times.4 mm or below. FIGS. 1 through 9 schematically show a general structure of the above-mentioned movement and a description thereof can be given as follows.
FIGS. 1-3 show a circular alarm clock movement seen from different views, respectively. The movement generally comprises a body 90 of a given diameter, a battery 91, an alarm setting rotor 92, an hour-setting rotor 93, a motor 94, a wheel or gear train 95, and a buzzer 96. FIGS. 4 and 5 show how the movement shown in FIGS. 1-3 is assembled to different kinds of case, respectively. FIG. 4 shows that the movement is assembled to a hole 901 of a rectangular case 900 and FIG. 5 shows that the movement is assembled to a hole 921 of a spherical case 920. FIGS. 6-7 are cross-sections showing interrelationship between the body 90, the alarm setting rotor 92, the hour-setting rotor 93 and the wheel train 95. In particular, FIG. 6 shows how a rotor 97 driven by the motor 94 is arranged within the body 90 to drive, via associated gear or gears, a second wheel 952, a minute wheel 954 and an hour wheel 956. FIG. 6 also shows how the hour-setting rotor 93 is arranged to mesh with the hour wheel 956 and the minute wheel 954. FIG. 7 shows how the alarm setting rotor 92 is arranged within the body 90 to cooperate with an upper wheel 98 which is in mesh with an alarm wheel 958 shown in FIG. 6. The upper wheel 98 in turn engages with a lower wheel 99 which meshes with the hour wheel 956 and can be moved upward and downward to control activation of the buzzer 91. The upward and downward movement of the lower wheel 99 with respect to the upper wheel 98 can be achieved by providing protrusions 982 and recesses 992 thereon, respectively, as shown in FIGS. 8 and 9. It is noted that, as is known in this art, within the body 90 of the movement there is a circuit substrate containing associated electric driving circuits and the like to complete the above-mentioned movement, although it is not specifically described herein.
In FIGS. 6 and 7, if the alarm wheel 958, the upper and lower wheels 98 and 99, the alarm-setting rotor 92, the buzzer 91 and related contact blades are removed, the alarm clock movement simply becomes a clock movement without an alarm function.
In practice, where it is desired that a movement be put into a case having a hole of, for example, 35 mm or below in diameter, only watch movements having a dimension of 30 mm.times.4 mm or below can be used. Since watch movements are more expensive to manufacture than clock movements, it will be a saving of cost if clock movements can be used in this case. This is possible where an increase in thickness of the movement due to a decrease in diameter of the movement is not important in many applied cases.
Applicant has found that the gear train itself does not occupy a large percentage of a total diameter of the movement. It has further been observed that the motor, the battery and the buzzer together consume a large space, and these components, arranged side-by-side with the gear train, contribute to the dimension an ordinary movement now exhibits.